Closed loop control is commonly used to regulate motor torques of high performance alternating current (AC) motors. In a typical closed loop control system of an electric motor, a target torque to be output by the electric motor can be input to the control system using a torque command. The control system then converts the torque command to a current command according to a pre-calculated look-up table. The look-up table includes data about mapping relationship between torque commands and their corresponding current commands. In some cases, multiple tables may be provided, each corresponding to a different direct current (DC) link voltage used to generate AC phase voltages through an inverter.
Each current command in the look-up table may also be referred to as an operating point. Calculation of operating points in one or multiple look-up tables is usually very time consuming. For example, it may take weeks or even months to determine all operating points in a look-up table.